Comprehension and eye movements in the processing of subject- and object-relative clauses: Evidence from dyslexia and individual differences

In this study, we examined eye movements and comprehension in sentences containing a rela-tive clause. To date, few studies have focused on syntactic processing in dyslexia and so one goal of the study is to contribute to this gap in the experimental literature. A second goal is to con-tribute to theoretical psycholinguistic debate concerning the cause and the location of the pro-cessing difficulty associated with object-relative clauses. We compared dyslexic readers (n = 50) to a group of non-dyslexic controls (n = 50). We also assessed two key individual differences variables (working memory and verbal intelligence), which have been theorised to impact reading times and comprehension of subject- and object-relative clauses. The results showed that dyslexics and controls had similar comprehension accuracy. However, reading times showed participants with dyslexia spent significantly longer reading the sentences compared to controls (i.e., a main effect of dyslexia). In general, sentence type did not interact with dyslexia status. With respect to individual differences and the theoretical debate, we found that processing dif-ficulty between the subject and object relatives was no longer significant when individual dif-ferences in working memory were controlled. Thus, our findings support theories, which as-sume that working memory demands are responsible for the processing difficulty incurred by (1) individuals with dyslexia and (2) object-relative clauses as compared to subject relative clauses.